The present invention relates to a hoisting apparatus for a cover of an electric arc furnace or similarly bulky object. Basically, two gantry arms extend across the cover. Traverse bars overlay the gantry arms and are provided with hoisting rods, which may selectively be lifted and lowered with the cover. The cover is raised by a hydraulic lifting mechanism, in the form of a plunger mechanism or a piston-cylinder device. The gantry and traverse arms are water cooled to protect the lifting rods and the lifting mechanisms.